A Measurement of the Fission Cross Section of Uranium-235 from 100 eV to 680 keV

We have measured the ratio of the ²³⁵U fission cross section to the ⁶Li(n, α) cross section at neutron energies from thermal to 680 keV. The Lawrence Livermore Laboratory electron Linac provided a pulsed source of neutrons, and energies were measured by time-o f-flight. The evaluated ⁶Li cross section was used to obtain σ(n, f) for ²³⁵U from 100 eV to 680 keV and to normalize the results to the accepted thermal fission cross-section value.